[Dashboards] Favorite a dashboard from within

[Erikg346]

Describe the feature:
Add the ability to favorite a dashboard from within a dashboard.

Describe a specific use case for the feature:
The favoriting of the dashboard is a great feature, but it relies on the user leaving their dashboard and going into the Dashboard Pages View, which is hard (if you have many dashboards) to find the one where you were just at to favorite it.

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[Heenawter]

Tagging in @elastic/appex-sharedux, since they own the favouriting feature :) I'm keeping the @elastic/kibana-presentation tag for now, since it's unclear who would really "own" this new functionality, but interested in thoughts from the SharedUX team.

[Dosant]

@Heenawter, This shouldn't be too difficult to implement. Here is a POC #201596 , ideally I'd reuse the component that we already have.
Here is what the POC looks like:

favorite.a.dash.mov

This works, but doesn't look neat. @andreadelrio, could you please take a look if we can improve this from a design perspective?

cc @teresaalvarezsoler